Image-receiving element for use in silver salt diffusion transfer photographic process

ABSTRACT

An image-receiving element useful for silver salt diffusion transfer photographic process, which comprises a support having coated thereon a diffusion transferred image-receiving layer primarily comprising colloidal silicon dioxide containing silver precipitating nuclei dispersed therein, said image-receiving layer being overcoated thereon with a layer containing condensation products derived from formaldehyde and barbituric acid or an alkylated barbituric acid and represented by the following formula:   WHEREIN R1 and R2 may be the same or different and are each -H, -CH3 or -C2H5, and n is a number from 1 to 10.

United States Patent 1 Tsuji et al.

[ Nov. 13, 1973 154] IMAGE-RECEIVING ELEMENT FOR USE IN SILVER SALT DIFFUSION TRANSFER PHOTOGRAPIIIC PROCESS [75] Inventors: Nobuo Tsuji; Takushi Miyazako;

Kinji Ohkubo; Kazunobu Kato, all of Kanagawa, Japan [73] Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan [22] Filed: Sept. 16, 1971 [21] Appl. No.: 181,223

[30] Foreign Application Priority Data Sept. 16, 1970 Japan 45/81111 [52] US. Cl. 96/76 R, 96/50 PL [51] Int. Cl G03c l/48 [58] Field of Search 96/29, 76, 50 PL; 260/294, 67.5

[56] References Cited UNITED STATES PATENTS 2,698,237 12/1954 Land 96/29 R 2,698,245 12/1954 Land 96/29 R 2,823,122 2/1958 Land.... 96/29 3,060,022 10/1962 Duerr 96/29 3,345,168 10/1967 Wagner et al. 96/29 3,445,228 5/1969 Beavers et al. 96/29 Primary Examiner-Norman G. Torchin Assistant ExaminerJohn L. Goodrow Alt0rney-Richard C. Sughrue et al.

[57] ABSTRACT An image-receiving element useful for silver salt diffusion transfer photographic process, which comprises a support having coated thereon a diffusion transferred image-receiving layer primarily comprising colloidal silicon dioxide containing silver precipitating nuclei dispersed therein, said image-receiving layer being overcoated thereon with a layer containing condensation products derived from formaldehyde and barbituric acid or an alkylated barbituric acid and represented by the following formula:

wherein R and R may be the same or different and are each -H, CI-I or C I-I and n is a number from 1 to 10.

10 Claims, No Drawings IMAGE-RECEIVING ELEMENT FOR USE IN SILVER SALT DIFFUSION TRANSFER PHOTOGRAPHIC PROCESS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an image-receiving element for use in a silver salt diffusion transfer photographic process.

2. Description of the PriorArt In the hitherto known diffusion transfer photographic processes wherein there is employed a light sensitive photographic material comprising a support having coated thereon a dispersion of fine particles of a light sensitive silver salt, such as a silver halide, in a hydrophilic binder such as gelatin, the light-sensitive layer thereof is exposed to light imagewise. The material is then contacted with a processing composition containing a developing agent to effect development of the light-sensitive silver salt. At this point, the exposed silver halide in the light sensitive layer is thereby reduced (developed), to form metallic silver. Concurrently therewith or subsequently thereto, the light sensitive material is processed with an agent capable of forming a water-soluble silver complex (fixing agent), whereby a water soluble silver complex is obtained by reaction of the unexposed (undeveloped) silver halide with this agent. When an image-receiving element having a layer, i.e., image-receiving layer, containing therein a substance dispersed in a hydrophilic binder which serves as catalyst for reduction of the above-described water-soluble silver complex (the substance therefore being silver precipitating nuclei, or so-called development nuclei), is brought concurrently into intimate contact with the aforementioned light-sensitive negative layer, the silver complex formed in the light sensitive layer is, at least in part, transferred from the light sensitive negative layer to the image-receiving layer by diffusion, where it is reduced to silver under the effect of the development nuclei contained therein. Thereby the positive images having a pattern corresponding to that in the original light sensitive negative layer are formed.

Naturally, in order to obtain the desired positive print, the receiving element has to be stripped off from the light-sensitive element. Thus, a coating film, a socalled stripping layer, is usually provided on the imagereceiving layer so as to facilitate the dissociation or stripping and to prevent a film of the diffusion transfer processing composition from attaching or remaining on the surface of the processed image-receiving layer. When the aforementioned dissociation is unsatisfactory and/or the processing composition remains the image surface of the image-receiving element is tainted and the quality of the images lowered remarkably. Furthermore, in the absence, on the image-receiving element, of such a stripping layer, the silver images formed on the image-receiving element, while stored frequently, undergo deterioration and/or the high light areas thereof yellow.

As materials for the aforementioned stripping layer, previously there have been employed, for example, gum arabic, hydroxyethyl cellulose, methyl cellulose, polyvinyl alcohol, polymethacrylate and sodium alginate.

Although the above-mentioned compounds are effective in providing the stripping layer to avoid the remaining of the processing composition on the surface of the positive print, and protecting the surface of the image-receiving sheet from being scratched during the handling of the same, they often present disadvantages that the transferred image develops a metallic lustre and/or that the transfer is inhibited, thereby lowering the density of the transferred images.

An object of the present invention is to provide the aforementioned image-receiving material which can result in a stable positive print which does not undergo, on storage, deterioration in its silver images or yellowing even in its high light areas.

Another object of the invention is to provide the aforementioned image-receiving material of which the surface is protected from being scratched on handling.

SUMMARY OF THE INVENTION The present invention provides an image-receiving element useful for silver salt diffusion transfer process, which comprises a support having coated thereon a dif fusion transferred image-receiving layer primarily comprising colloidal silicon dioxide containing therein silver precipitationg nuclei in a dispersed form, said image-receiving layer being overcoated thereon with a layer containing condensation products derived from formaldehyde and barbituric acid or from formaldehyde and an alkylated barbituric acid and represented by the following formula wherein R and R may be the same or different and are each --I-I, -CI-I or --C I-l and n is a number from I to 10.

DETAILED DESCRIPTION OF THE INVENTION Typical examples of the above-described compounds are illustrated in the following:

These compounds can be easily prepared in a conventional manner, for example, by reacting, in the presence of an alkali catalyst, barbituric acid or an alkylated barbituric acid with formaldehyde. In the hereinafter described Example I, the method is described in detail, taking the synthesis of Compound I for example, although other compounds can also be prepared in the same manner by using the corresponding alkylated barhituric acid.

In synthesizing the compounds, those with varied n values can be obtained by varying the mixing proportions of the barbituric acid or the alkylated barbituric acid to formaldehyde. The condensation products thus prepared are usually a mixture of compounds with varied n values. However, such mixtures can also accomplish sufficiently the effects intended by the present invention. The preferred compounds from the standpoint of accomplishing the above-described objects of the present invention are those wherein n is from 1 to 10, and more particularly from 2 to 5. These compounds are all water-soluble and applied, in the form of their aqueous solution, to the surface of the image-receiving element. The coating weight of these compounds is suitably in the range of from 0.1 to 2 glm and more suitably from 0.3 to 10 g/m. When the coating weight is less than this range, the preventing effect against attachment of the processing composition tends to be lessened while, when the coverage exceeds this range, the diffusion transfer tends to be inhibited.

elements utilizing such highly active silver precipitating nuclei can also be preferentially used as high speed diffusion transfer photographic materials. The specification of U. S. Pat. No. 2,698,237 describes a method for preparing such highly active silver precipitating nuclei, wherein a water-soluble metal salt and water-soluble sulfide are admixed in particulate silicon dioxide, thereby forming a precipitate of the resulting waterinsoluble metal sulfide. Any other hitherto known simi lar technique can be applied to the present invention.

The colloidal silicon dioxide which incorporates thereinto the silver precipitating nuclei and is used as the so-called binder is often called silicic acid anhydride and is per se an acidic substance, so that, when dispersed in water, it is in part hydrated to form silicic acid.

The pKa, of silicic acid is 9.8 and the pKa is 12.16. It is desirable that the silicon dioxide used in the invention be in the form of particles as fine as possible. Ex-

Maker Trade name Form pH Monsanto Chemical Co Santocel 54 4% aqueous dispersion 3, D Santocel C o u 3,

Santoeel L 4. 3.

Santocel FRC 3. Aerosil 130 3. 6-4. 3.6-4.

Sylold 308.... 2. Syloid 404.. 7. Syloid AL- 3.

As the support for use in the image-receiving element according to the present invention, there may be employed any suitable material, for example, films or sheets of resins such as polyethylene terephthalate, cellulose diacetate, cellulose triacetate, polycarbonate, polyvinyl chloride, or polyethylene, baryta-coated paper, resin-coated papers, glass plates, metal plates, plates made of earthen-ware or the like material.

As the silver precipitating nuclei according to the present invention, there may be employed normally water-insoluble metal sulfides, metal selenides, or colloidal heavy or noble metals. It is desirable that the silver precipitating nuclei in the image-receiving element be of high activity. In particular, the image-receiving The image-receiving layer of the present invention can be prepared by dispersing the aforementioned silver precipitating nuclei into such a colloidal silicon dioxide and applying the dispersion to a support followed by drying. The image receiving element according to the present invention is obtained by coating the imagereceiving layer with the stripping layer comprising the condensation products of the invention.

The thus obtained image-receiving elements can accomplish the aforementioned objects and are very useful as diffusion transfer photographic materials.

The present invention will be further explained in greater detail with particular reference to the following Comparison Examples and Examples.

COMPARISON EXAMPLE 1 An aqueous dispersion of silver precipitating nuclei was prepared by mixing the following ingredients:

5% by weight, Aqueous Solution of Santocel 54(Trade Name, Silicon Dioxide, Manufactured by Monsanto Chemical Co.) -250 cc 2% by weight, Aqueous Solution of Lead Acetate (trihydrate) l.5 cc

3% by weight, Aqueous Solution of Cadmium Acetate (dihyrate) --2.3 cc

5% by weight, Aqueous Solution of Zinc Nitrate (pentahydrate) 5.0 cc 3% by weight, Aqueous Solution of Sodium Sulfide (nonahydrate) l.0 cc

6% by weight, Aqueous Solution of Saponin 5.0 cc and was applied to the surface of a baryta-coated paper at a coverage of 20 cc/m The image-receiving element thus obtained was then brought into intimate contact with an imagewise exposed Neopan SSS Sheet Film(Trade, Name, high speed photographic negative material using silver iodobromide emulsion, provided by Fuji Photo Film Co., Ltd.) in a manner such that the image-receiving layer may be surface contacted with the emulsion surface, between which was spread a viscous diffusion transfer photographic processing composition having the following composition:

Water l,860 g Sodium Salt of Carboxymethyl Cellulose 1 17 g Sodium Sulfite (anhydrous) 78 g Sodium Hydroxide 74.6 g

Sodium Thiosulfate (crystalline) l4.5 g

Citric Acid 38.5 g

Hydroquinone 52 g The negative material and image-receiving material were kept in contact with each other for seconds to effect diffusion transfer of images, after which they were separated. The resulting positive print on the image-receiving material had a film of the processing composition deposited or remaining all over the surface thereof, and was tainted brown.

COMPARISON EXAMPLE 2 To the coated surface of the image-receiving element prepared in Comparison Example 1 was applied a solution having the following composition at a coverage of 20 cc/m and then dried.

Gum Arabic (made by Iwaki Seiyaku Co., Ltd.)

Distilled Water lOO cc 6% Aqueous Solution of Saponin 2.0 cc

The image-receiving element thus obtained was processed in the same manner as in Comparison Example 1.

After a 15 second processing, the image-receiving material was separated from the negative to find that all the coating film of the processing composition attached to the negative element, but not to the image-reciving element. However, the maximum density of the positive images obtained by this diffusion transfer procedure was 0.80 in terms of reflection density. Furthermore, the transferred images in the areas of high density assumed a metallic lustre.

' EXAMPLE 1 On top of the coated surface of the image-receiving material prepared in Comparison Example 1, an aqueous solution having the following composition was coated at a coverage of 20 cc/m and then dried, thereby forming a stripping layer.

Barbituric Acid-Formaldehyde Condensation Products (average molecular weight is 510) (the preparation thereof being as described below) -l.5 g

Distilled Water cc 6% Aqueous Solution of Saponin 2.0 cc

IN Aqueous Solution of Caustic Soda to adjust the pH of the solution to -7 Preparation of the Above-Described Condensation Polymer:

Into a 200 cc round bottom flask equipped with a stirrer and a condenser were added 50 g of barbituric acid, g of 37% aqueous solution of formaldehyde and 0.3 g of sodium hydroxide, after which the mixture was stirred at a temperature of 100C.

Thereafter, agitation was continued with the condenser removed, thereby evaporating the water. In the course of the agitation the contents in the flask slowly thickened, which finally made it impossible to effect agitation, at which time the reaction was discontinued. The resulting products weighed 5 g and were brown in color. The products were analyzed as to their structure using LR. and N.M.R. spectra. As the result, the main components in the products were presumably assigned the following formula:

HOHzC The molecular weight of the main products was about 5 10 in terms of average molecular weight and the products were also found to be a mixture of trimer (n=3) and tetramer (n =4). The condensates were soluble in water and aqueous solutions of alkalis.

The image-receiving element thus obtained was then diffusion transfer processed in the same manner as in Comparison Example 1, thereby obtaining a positive print without any developing composition film remaining thereon.

The maximum density of the transferred positive images was 1.40 in terms of reflection density, and no metallic lustre appeared even in the areas of high density.

EXAMPLE 2 The coated surface of the image-receiving element prepared in Comparison Example 1 was overcoated with an aqueous solution having the following composition at a coverage of 20 cc/m and then dried, thereby forming a stripping layer.

5,5-Dimethylbarbituric acid-Formaldehyde Condensation Polymer (average molecular weight 550) 2.0 g

Distilled Water lOO cc 6% Aqueous Solution of Saponin 2.0 cc

1N Aqueous Solution of Caustic Soda added to adjust the pH of the solution to -7.0

The image-receiving element thus obtained was then subjected to the same diffusion transfer processing as in Comparison Example 1, thereby obtaining a positive print on which no developing composition film remained.

The maximum density of the transferred positive images was 1.50 in terms of reflection density, and no me tallic lustre was observed even in the areas of high density.

EXAMPLE 3 The coated surface of the image-receiving element prepared in Comparison Example 1 was overcoated with an aqueous solution having the following composition at a coverage of ctr/m thereby preparing an image-receiving element with a stripping layer.

5-Methyl-5-Ethylbarbituric Acid- Formaldehyde Condensation Polymer (average molecular weight 470) 2.0 g

Distilled Water 100 cc 6% Aqueous Solution of Saponin -2.0 cc

1N Aqueous Solution of Caustic Soda added to adjust the pH of the solution to 7,0

The image receiving element thus obtained was then diffusion transfer processed in the same manner as in Comparison Example 1, thereby obtaining a positive print on which no developing composition film remained.

The maximum density of the transferred images was l.35 in terms of reflection density, and no metallic lustre was observed even in the areas of high density.

As is evident from the above-described examples, the image-receiving element coated with the compounds of the present invention is markedly superior to the hitherto known ones coated with the other compounds, as for example in that no developing composition film is deposited nor left on the positive element of the invention and in that the maximum density of the transferred images is high. Furthermore, according to the imagereceiving element having coated thereon the compounds of the present invention, scratching during handling of the same is avoided and no developing composition film remains on the positive print surface, so that any deterioration of the resulting silver images or brown-tainting by oxidation products contained in the processing composition will not occur.

Although the invention has been described in considerable detail with reference to certain embodiments thereof, it will be understood that variations and modifications can be effected without departing from the spirit and scope of the invention as described hereinabove and defined in the appended claims.

What is claimed is:

1. An image-receiving element adapted for use in silver salt diffusion transfer photographic process, which comprises a support having coated thereon a diffusion transfer image-receiving layer primarily comprising colloidal silicon dioxide containing silver precipitating nuclei dispersed therein, said image-receiving layer being overcoated thereon with a layer containing condensation products of formaldehyde and b arbituric acid or of formaldehyde and an alkylated barbituric acid and represented by the following formula:

4. An image-receiving element as claimed in claim ll, wherein said condensation products are a mixture of compounds of the formula:

HOHzC HOHzC 5. An image-receiving element as claimed in claim 1, wherein said condensation products are a mixture of compounds of the formula:

6. An image-receiving element as claimed in claim 1, wherein said condensation products are coated on the image-receiving layer at a coverage ranging from 0.1 to 2 glm 7. An image-receiving element as claimed in claim 1, wherein said condensation products are coated on the image-receiving layer at a coverage ranging from 0.3 to 1.0 gfm 8. An image-receiving element as claimed in claim 1, wherein said support is selected from the group consisting of films and sheets of synthetic resins, barytacoated paper, resin-coated papers, glass plates, metal plates, and plates made of earthen ware.

9. An image-receiving material as claimed in claim 1, wherein said silver precipitating nuclei are selected from the group consisting of metal sulfides, metal selenides, and colloidal heavy and noble metals.

10. An image-receiving element as claimed in claim 9, wherein said metal sulfides are prepared by admixin g, in particulate silicon dioxide, a water-soluble metal salt with a water-soluble sulfide to form the precipitate of the resulting water-insoluble metal sulfide. 

2. An image-receiving element as claimed in claim 1, wherein n is a number of from 2 to
 5. 3. An image-receiving element as claimed in claim 1, wherein said condensation products are a mixture of compounds of the formula:
 4. An image-receiving element as claimed in claim 1, wherein said condensation products are a mixture of compounds of the formula:
 5. An image-receiving element as claimed in claim 1, wherein said condensation products are a mixture of compounds of the formula:
 6. An image-receiving element as claimed in claim 1, wherein said condensation products are coated on the image-receiving layer at a coverage ranging from 0.1 to 2 g/m2.
 7. An image-receiving element as claimed in claim 1, wherein said condensation products are coated on the image-receiving layer at a coverage ranging from 0.3 to 1.0 g/m2.
 8. An image-receiving element as claimed in claim 1, wherein said support is selected from the group consisting of films and sheets of synthetic resins, baryta-coated paper, resin-coated papers, glass plates, metal plates, and plates made of earthen ware.
 9. An image-receiving material as claimed in claim 1, wherein said silver precipitating nuclei are selected from the group consisting of metal sulfides, metal selenides, and colloidal heavy and noble metals.
 10. An image-receiving element as claimed in claim 9, wherein said metal sulfides are prepared by admixing, in particulate silicon dioxide, a water-soluble metal salt with a water-soluble sulfide to form the precipitate of the resulting water-insoluble metal sulfide. 